1. Field of the Invention
The present invention relates to a method and a device for monitoring a meshing process of a meshing pinion of a starter motor for a vehicle drive, in which an armature of the starter motor is moved by a magnet.
2. Description of the Related Art
Starter motors are known in which a meshing pinion of the starter motor is meshed with a ring gear of a vehicle drive, in particular of an internal combustion engine, during the starting operation with the aid of a solenoid. For example, the meshing pinion closes a contact bridge in the solenoid during or prior to reaching a meshed end position, thus supplying the electric starter motor with current.
In the ideal case, the meshing pinion of the starter motor and a corresponding ring gear in the vehicle drive are rotated relative to one another in such a way that the meshing pinion slides directly into the ring gear when a solenoid is activated. However, it is also possible for a tooth of the pinion to initially completely or partially overlap with a tooth of the ring gear during the meshing process, thus preventing the direct meshing. In particular a worn pinion or ring gear may result in a situation where the starter motor begins to rotate, and the meshing pinion does not mesh with the ring gear due to the tooth position. Instead, the teeth of the meshing pinion and the teeth of the ring gear may slide over one another, so that the vehicle drive is not driven by the starter motor.
In conventional starter motors, for example, a check is made via a function of the internal combustion engine as to whether a meshing process has concluded after a determined time period. If no successful meshing process can be detected after this determined time period, the meshing process is terminated, for example, and may be restarted. However, this may have adverse effects on the operation of starter motors in start-stop systems, in which the vehicle drive is to be restarted in the shortest possible time.